Price data and calendar alignment
Calculations use daily historical adjusted-close data. For each year, the requested start date moves forward to the nearest available trading day and the end date moves backward to the nearest available trading day. Windows that cross December continue into the following year.
Full-year seasonal path
Each valid trading year is normalized to an index level of 100 at its first observation. Trading observations are interpolated across Jan–Dec calendar progress, and the platform averages the aligned yearly paths point by point.
Selected-window statistics
- Return = end adjusted close ÷ start adjusted close − 1.
- Win rate = percentage of observed returns above zero.
- Average and median are calculated across all valid yearly windows.
- Cumulative return compounds the sequence of historical window returns.
- Annualized return is the geometric mean across those observations.
Data quality and interpretation
Symbols with insufficient or unusable history are excluded from a calculation. Corporate-action adjustments, provider revisions, survivorship, regime changes and multiple testing can affect results. Recheck material decisions independently.